1. Technical Field
The present disclosure relates to a display apparatus such as a liquid crystal display (LCD), and especially to power management in a display apparatus and LCD.
2. Description of Related Art
LCDs are widely used in various information products such as notebooks, personal digital assistants (PDAs), video cameras, and the like. FIG. 4 is a block diagram of one such LCD 100. The LCD 100 includes a power board 11, a control circuit 12, and a liquid crystal panel 13. The power board 11 is electrically coupled to the control circuit 12, providing operating power to the control circuit 12. The control circuit 12 is electrically coupled between the liquid crystal panel 13 and an external video source 14 such as a computer host providing video signals thereto, and controls a working mode of the liquid crystal panel 13 according to output of the video source 14.
In operation, the control circuit 12 converts video signals output by the video source 14 into corresponding driving voltages, and provides the driving voltages to the liquid crystal panel 13. Thereby, the liquid crystal panel 13 is directed in a normal mode, displaying images corresponding to the video signals. Upon detecting that no video signal has been output by the video source 14 within a predetermined time period, the control circuit 12 switches the liquid crystal panel 13 from the normal mode to a standby mode, so as to conserve power consumed by the liquid crystal panel 13.
In standby mode, no image is displayed, and accordingly overall power consumption of the LCD 100 is minimal. In the described LCD 100, however, the power board 11 continues to provide power voltage to the control circuit 12 even when the liquid crystal panel 13 is in standby mode, consuming un-needed power.
What is needed, therefore, is an LCD and a display apparatus that can overcome the described limitations.